In my defense, he had help. Take a big scoop of Galaga, a few homages to Tempest, and add a slammin’ soundtrack to get a basic picture of Symphony, a vertical bullet-hell shooter from indie developer Empty Clip Studios. Now here’s the twist: that slamming soundtrack? You pull it in from your own music library and playlists, and each song’s rhythms dictate the pace of the game from second to second.

At a special advanced preview for Symphony, I ran through a very eclectic playlist that ran from casual armageddon to hyper-violent death-a-thon. But the Candy Man belting out kicky, syncopated jazz number “There is Nothing Like a Dame” made Symphony turn on me. Hard.

That kind of variation gives Symphony’s quirky strum and drang considerable lift, but it still has a problem. A very interesting problem…something I’ve never, ever called a game out on before.

But to understand its issues, you need a full appreciation of what Symphony does.

It starts by turning your beloved music against you. The plot explains this with an evil entity who’s corrupted your favorite musicians and composers, charging you to take them back via superior firepower. You import music from your platform’s hard drive and select a song to play against. Symphony takes a moment to analyze the song (which does have minimum length requirements…sorry, They Might Be Giants fans), then generates a game around it. Your song is the level.

Pacing, point quotas, and length all depend on the track. Success depends on scooping up note-shaped points dropped by baddies you've atomized with your handy little gunship, up to and including power-ups and chained point bonuses doled out via killstreaks. That’s not always easy, because if you pick songs with a pounding beat, Symphony gets real busy. This game's not afraid to throw a variety of enemies with wildly different attacks at you at the same time when the soundtrack dictates it. All the more reason to grab points and upgrade your ship’s four weapon slots from blasters to missiles, scatterguns, and giant note-hurling subwoofers.

Bosses show up when you hit a certain point threshold (cumulative across “levels”), which is how I drew one right in the middle of Spandau Ballet’s “Gold” — weirdly appropriate, once we all stopped laughing. After demolishing Mr. Boss, the game went right back into the onslaught for the rest of the song.

Unfortunately, minus those tempo changes, the boss fights themselves — I took out three — were identical. A mask-like face zips back and forth at the top of the screen, firing at you while a gauntlet of panels rain down. Considering the insanity Symphony routinely fastballed at me, these marked the easiest challenges in the game…to the point where I have to suspect they’re only mini-bosses leading up to something fairly soul-crushing. A few hints point to something much bigger on the horizon.

Minus that lapse into retro-flavored cliché, the replayability on this looks crazy. So long as you still have something left untouched in your 20+ GB library of music, you can get new content out of Symphony. iTunes is your DLC. Import it. Load it. Run it. All together, I’m not at all surprised Symphony took home both the Technical Achievement and GameStop PC Digital Download awards at the 2012 D.I.C.E. Indie Game Challenge.

And maybe you noticed it, but that’s the problem. Right there. Symphony isn’t an iOS, Windows Mobile, or Android game. You’ll find it on Steam, Gamestop Digital, Origin, GOG, and Gamefly Digital sometime in early August for your PC and PC-friendly Macs.

Music is a mobile genre now. All the content Symphony wants to leverage lives in my pocket, and while I absolutely store my music on a laptop or a desktop, I generally access it through my phone or tablet. And I access it most often while I'm out and about, not tethered to a computer. Symphony might find a niche with laptop gamers — I played it on a MacBook — and I hope it does, but I can't help thinking it's on the wrong platform.

As is, I'm concerned it'll get swallowed up somewhere between the free-to-play shooters and triple-A titles on Steam or Origin. If I'm at my desktop, I'll fire up Team Fortress 2. Holding an iPad, I'm playing Symphony for days, constantly looking for new songs to beat. I spent about an hour bouncing around on someone else's playlist, and that kept me fascinated and engaged in a genre I've frequently bypassed since the late '90s. Match this gameplay to my personal soundtrack, stuff I know inside and out, and put it on a platform I most closely associate with that material, and I'm all in.

And if Empty Clip can port it over wholesale and get the controls right, the Symphony I played completely outstrips anything I've seen in its class on the App Store. Period.

Believe me, I know it sounds fairly disingenuous to hit a game based on the hardware it runs on, but Symphony's special features create special circumstances. And indeed, I'm informally told Empty Clip wants to get it on iProducts…after the Steam launch. That's really where it belongs. On mobile, Symphony's a standout. On PC, it could easily get lost in the shuffle. Symphony doesn't deserve that. Few games do.